The present invention relates to the field of aircraft maintenance. More specifically, the present invention relates to a system and method for recording and analyzing reliability data for an aircraft during a dynamically-planned maintenance check of the aircraft.
Aircraft maintenance occupies a key position in airline operation because such maintenance is essential to the safety of passengers and the reliability of airline schedules. Each aircraft has its own maintenance requirements which are designed to keep the aircraft in an airworthy condition. These aircraft maintenance requirements typically originate from the aircraft's manufacturer, and can be revised throughout the life of the aircraft by the aircraft manufactures, the Federal Aviation Administration (FAA) and/or the Maintenance Review Board (MRB).
These aircraft maintenance requirements are documented in aircraft-specific MRB documents. An MRB document details each task that must be accomplished on a particular aircraft, the requirements of that task, and the frequency with which the task must be performed. The MRB document includes tasks that need to be accomplished anywhere from once a day to once every 20 years, as well as tasks that need to be accomplished after the aircraft has achieved a specific number of flight hours, flight cycles or other triggering indicia. For most major aircraft types, the MRB document lists somewhere between 800 to 2,000 different tasks.
The MRB document details a very complicated maintenance schedule. To ensure compliance with the MRB document, airlines must implement various tracking programs to monitor for the dates when tasks come due, as well as to log the completion of those tasks and any corrective actions taken.
Because an aircraft produces revenue only when it is flying, it is essential for airline management to keep maintenance time at a minimum. Thus, airlines commonly group tasks together (into letter-checks) rather than perform the tasks one at a time as they come due. Letter checks commonly include “A checks”, “B checks”, “C checks” and “D checks”, with A checks occurring most frequently and having the fewest number of tasks. A and B checks typically can be performed overnight in a “line maintenance” environment, in which, assuming no complications arise, the aircraft typically loses little or no flight time. In this environment, the aircraft remains airworthy because it can be reassembled quickly.
Conversely, C and D checks comprise a greater number of tasks, many of which require a substantial amount of time to complete. Thus C and D checks are typically performed in a heavy maintenance environment in which the aircraft is taken out of service. In this environment, an aircraft is taken into a hanger, where it is taken apart, inspected, fixed and reassembled during the course of one week to over a month. During this heavy maintenance period, non-routine tasks (those not detailed in the MRB document) are identified (often as a result of an inspection mandated by the MRB document), and parts that have reached their hard limits specified by the MRB document are replaced. Upwards of 300 persons (including cleaners, mechanics, lead mechanics, inspectors and lead inspectors) may work on the maintenance of the aircraft. In addition, a management team including managers, supervisors, directors, production coordinators and shops managers coordinate the completion of the maintenance. This maintenance team typically works in three shifts a day, seven days a week, to complete the needed maintenance.
To minimize the number of days the aircraft is removed from operation, a maintenance plan must be developed to assign and monitor the completion of tasks. The development of such a plan is made more difficult by the identification of non-routine tasks during the maintenance, back orders on parts which preclude the completion of certain tasks and the failure to complete timely critical path tasks (those which prevent subsequent tasks from being completed). No computer-based method exists to dynamically prepare such a maintenance plan using dynamically changing information, such as available labor hours, sequence and dependency of tasks, and the addition of non-routine tasks.
Airlines can further save costs by escalating, when permissible, the intervals at which tasks are performed. Based upon reliability data collected by an airline during maintenance of their own aircrafts, the FAA may allow the airline to more favorably escalate tasks beyond the requirements of the MRB document (i.e, require the task to be performed at longer intervals). Thus, if a task to inspect a particular part is performed as required every six months, and the part is consistently (throughout the fleet) in good condition, the task may be escalated to one a year (or some other interval). Such escalations of tasks can significantly affect the time and cost of maintaining an airline's fleet of aircraft. A reliability program thus modifies, for a particular airline only, an aircraft's MRB document by changing the intervals required between overhauls, inspections and checks of aircraft equipment. Guidance on reliability program elements is listed in Advisory Circular (AC) 120-17, Maintenance Program Management Through Reliability Methods, as amended, the Airline/Manufacturer Maintenance Program Planning Document, MSG-2/3, and/or Maintenance Tasks.
A reliability program can further help airlines determine whether individual warrantied parts have met the manufacturer's predicted life limits. Often, manufacturers of aircraft parts, especially engine parts, guarantee that the part will not fail before a specified number of hours. Thus, a reliability program can enable airlines to get warranty money back from warranty administration on that part if the part does not meet the manufacturer's predicted life limits. There is no computer-based program for monitoring the reliability program of an entire fleet of aircraft as it relates to the requirements of the MRB document, which uses data dynamically collected during the process of maintenance.
Another aspect of an aircraft maintenance program for an airline is the proper training of its personnel. The FAA has very strict standards regarding the training required of aircraft mechanics. Before permitting a mechanic to perform a task, the FAA requires that the mechanic have been previously supervised doing the task or specifically trained for the task. The FAA additionally requires much of the training to be performed on a recurrent basis. Therefore, airlines must monitor and log all training received by its maintenance employees.
Airlines must also maintain a significant number of publications, such as the MRB document, training manuals, maintenance manuals, illustrated parts catalogs, structural repair manuals, aircraft wiring diagrams and a general engineering and maintenance manual. Presently, these documents are mostly maintained in paper format.
No system presently exists to integrate all of the above-listed facets of a successful aircraft maintenance program. Additionally, no system presently exists to dynamically manage an aircraft's MRB document, to dynamically monitor for the dates when tasks are due on an aircraft, to log the completion of tasks and corrective actions taken on an aircraft, to dynamically prepare a maintenance plan, to dynamically collect reliability data or to dynamically collect personnel training records. Accordingly, there is a need for a system and method for dynamically managing, in real-time, aircraft maintenance requirements.